The present invention relates to a golf club head and, more particularly to an improved wood-type golf club head capable of generating greater club head speed during a swing due to increased aerodynamic performance and decreased drag.
A critical factor in improving the distance of a golf shot is to increase the club head speed during a golf swing and to increase the kinetic energy transferred to the ball when contact is made. In a conventional wood-type golf club head, the head contains a substantially flat face with horizontal grooves on the surface which makes contact with the ball during a shot. As the club is swung, air creates drag on the club head because of its relatively high drag coefficient. During the swing, air travels into the face and over the top and bottom of the club head. At the top and bottom of the head the air forms a boundary layer which produces a drag force. As the air flows over the top and bottom of the club head a wake or area of low pressure is created at the back of the club head. During the golf swing, a high pressure area at the face of the club head and the low pressure area at the back of the club head contribute to the drag force thereby impeding optimum club head speed.
Certain references disclose placing passages through the golf club head to allow air to flow through the club head via the passages toward the back of the club head thereby alleviating the low pressure wake. U.S. Pat. No. 3,794,328 to Gordon discloses a wood-type golf club head having two substantially horizontal passages formed through the golf club head extending from the face to the back of the club head. The passages are located at the toe and heel of the golf club head so as to not interfere with the striking surface at the club head's face. U.S. Pat. No. 4,809,982 to Kobayashi discloses a golf club head having one or more passages therein which extend from the back of the club head either diagonally to the top of the club head or, alternatively, diagonally to the bottom of the club head. The passage is designed to allow air from the boundary layer at the top or bottom of the club head to enter the passage and flow towards the back of the club head thereby increasing the pressure at the rear of the club head and decreasing the drag.
Although these references help to decrease the drag of a golf club head during a swing, there is still a considerable amount of drag created by the face of the golf club head at the striking surface. Moreover, since a considerable low pressure area still exists at the back of the club head during a swing, a relatively high pressure gradient exists between the face and back of the club head.
It is therefore an object of the present invention to provide a wood-type golf club head which is capable of decreasing the drag of the club head thereby increasing club head speed during the golf swing to increase the distance of a golf shot.
It is also an object of the present invention to provide an improved wood-type golf club head which is capable of allowing air to pass therethrough without impeding the grooves located at the face of the golf club head and without sacrificing control over the golf shot.